Protective device for condenser tubes



Oct. 14, 1969 R. J- STOKER PROTECTIVE DEVICE FOR CONDENS ER TUBES Filed Jan. 22, 1968 I INVENTOR. ROBfRT J. STOKER ATTORNEY United States Patent PROTECTIVE DEVICE FOR CONDENSER TUBES Robert J. Stoker, Phillipsbnrg, N.J., assignor to Ingersoll- Rand Company, New York, N.Y., a corporation of New Jersey Filed Jan. 22, 1968, Ser. No. 699,710 Int. Cl. F28b 1/00; F28f 19/00; F28d 7/00 US. Cl. 165-110 8 Claims ABSTRACT OF THE DISCLOSURE A baffle arrangement for use with a steam surface condenser of the type having a shell in which there are a plurality of tube bundles which carry cooling fluid for condensing steam. The battle arrangement deflects incoming steam so that it flows between the tube bundles and thereby insures that there is no direct impingement of high velocity steam on the top of the tube bundles. The arrangement is designed to minimize pressure losses so that it may be placed over the entire inlet of the condenser or only in those regions where the steam is entering at maximum velocity.

BACKGROUND OF THE INVENTION This invention relates to steam surface condensers and in particular to condenser tube protective devices for use with such condensers. The invention provides apparatus for preventing direct impingement of entrained high velocity water droplets on condenser tubes.

If steam to be condensed by a surface condenser contains high percentage of moisture, water droplets are formed and entrained in the steam flow. These water droplets are often accelerated to high velocities. When the water droplets impinge on condenser tubes, erosion of these tubes occurs. After a period of time this erosion causes a failure of the tubes and they must be replaced. Replacement of condenser tubes is a costly operation, which requires a long period of shutdown.

Prior to this invention, baffles, screens, and other apparatus have been inserted between the inlet of the condenser and the tube bundles. Such apparatus was designed to prevent direct impingement of moisture droplets on the tube bundles. Such prior apparatus, however, caused high pressure losses resulting in poor condenser performance. A second approach is to use harder tube material to reduce failure due to erosion. This, however, does not overcome the problem as even the harder material is subject to eventual failure. In addition, the harder material is costly resulting in a greater initial cost of the condenser.

SUMMARY It is therefore the principal object of this invention to provide novel apparatus which reduces tube failure due to erosion caused by direct impingement of moisture droplets on the condenser tubes.

It is a further object of this invention to provide apparatus for proteceting condenser tubes which does not significantly increase pressure loses in the condenser.

In general, the foregoing and other objects are carried out by providing in combination, a condenser having an inlet for steam to be condensed, a plurality of spaced apart tube bundles for carrying cooling fluid and apparatus for preventing direct impingement of high velocity steam against the tube bundles closest to the inlet comprising: a plurality of spaced apart first baflle means positioned between said inlet and said tube bundles; a plurality of spaced apart second baffle means positioned between said first baflle means; said first and second baffle means being positioned with respect to each other and to said tube bundles for directing the major portion of steam to be condensed between said tube bundles.

BRIEF DESCRIPTION OF THE DRAWING The invention will be described in connection with the following drawing wherein:

FIG. 1 is a top plain view of a condenser employing one embodiment of this invention;

FIG. 2 is a view showing an impingement protecting device in accordance with this invention; and

FIG. 3 is a perspective view of the impingement protecting device of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing and in particular to FIG. 1, there is shown a condenser generally indicated at 1. This condenser includes a shell having walls 2 and an inlet 3. The condenser 1 may be provided with the usual feed water heater 4. As best shown in FIG. 2, a plurality of spaced apart tube bundles generally indicated at 5 are mounted within the condenser. Each of the tube bundles 5 is made up of a plurality of tubes 6 which carry a cooling fluid such as water for condensing steam.

The area of maximum velocity incoming steam is indicated in broken lines as at 7. This area will depend upon the conditions of service and the type of turbine actually used. An impingement protecting device generally indicated at 10 and best shown in FIGS. 2 and 3 is preferably placed in each area 7 of maximum velocity incoming steam.

The impingement rack 10 is mounted on support plates 11 which may also be used to support tube bundles 5. Support plates 12 are mounted on plates 11 in any suitable manner such as by welding. First baflie .means 15 comprising a plurality of spaced apart large diameter pipes extend between the plates 12 and are located between the inlet and the tube bundles 5. The longitudinal axis of the pipes 15 is parallel to the longitudinal axis of the tube bundles 5. Each pipe 15 is preferably of a diameter large enough to substantially cover the width of the tube bundle below it. The pipes 15 are spaced apart a distance approximately equal to the distance between the tube bundles 5. If desired, some means other than pipes may be used although a convex surface facing the inlet is preferred since this aids in reducing pressure losses.

A second baflle means generally is indicated at 16 is placed between the inlet and the first baflle means 15 and is also positioned between the spaced apart pipes 15. This second baffle means 16 includes pipes 17 extending between plates 12 and plates 18 secured to the pipes 17 extending downwwardly therefrom. The longitudinal axis of the plates 18 is parallel to the longitudinal axis of the pipes 15. As in the case of the pipes 15, the pipes 17 may be replaced by some means having a convex surface facing the inlet of the condenser.

Steam entering the inlet of the condensed will follow a path indicated by the arrows 20. Such steam will strike the pipes 17 and 15 and flow downwardly through the passage 21 between tube bundles 5. The plates 18 insure that the incoming steam does not directly impinge on the tube bundles 5 at an angle.

Some of the steam passing between the tube bundles 5 in the passage 21 will be attracted to the cold tubes and condensed. Tube bundles lower than those shown in FIG. 2 may be positioned in the path 21 but by the time the steam reaches these tube bundles suflicient condensing will have taken place so that the velocity will have de creased sufficiently so that erosion damage will be almost eliminated from the direct impingement of the moisture droplets on these tube bundles.

Obviously erosion of the battle means 15 and 16 occur, but such erosion will not cause unnecessary shutdown of the condenser. Some erosion of these plates is permissible since they are not used to carry cooling water. When the baffie means 15 and 17 have eroded to such an extent that they are no longer effective to direct the flow of steam around the tube bundles, the bafile means can be replaced at a cost much less than the cost of replacing the tubes 6.

The use of round pipes 15 and 17 insures proper flow of steam and insures that pressure losses normally associated with prior baffie arrangements are substantially reduced. Although the tube bundle protecting rack is preferably placed in areas where there is a highest velocity incoming steam, the pressure losses are so slight that the rack may be placed throughout the inlet of the condenser.

It is apparent from the foregoing that the objects of this invention have been carried out. It is intended, however, that this invention be limited solely by that which is within the scope of the appended claims.

I claim:

1. In combination, a condenser having an inlet for steam to be condensed, a plurality of spaced apart tube bundles for carrying cooling fluid and apparatus for preventing direct impingement of high velocity steam against the tube bundles closest to said inlet comprising:

a plurality of spaced apart first bafile means positioned between said inlet and said tube bundles;

a plurality of spaced apart second baflle means positioned between said first bafile means;

said first and second baffie means being positioned with respect to each other and to said tube bundles for directing the major portiOn of steam to be condensed between said tube bundles.

2. The combination of claim 1 further comprising means for supporting said first and second baffie means.

3. The combination of claim 2 wherein said first and second bafile means are a plurality of pipes.

4. The combination of claim 3 wherein the longitudinal axis of each of said first and second batfie means is parallel to the longitudinal axis of said tube bundles.

5. The combination of claim 4 wherein said second baflle means is positioned between said inlet and said first bafile means and said second baffle means further comprises plate means extending downwardly between a pair of said first bafile means.

6. In combination, a condenser having an inlet for steam to be condensed, a plurality of spaced apart tube bundles for carrying fluid and means for preventing direct impingement of high velocity steam against the tube bundles closest to said inlet comprising:

a plurality of spaced apart first bafiie means mounted in said condenser and positioned between the inlet and the tube bundles;

each of said first baffle means overlying one of said tube bundles; and

a plurality of spaced apart bafile means mounted in said condenser and positioned between said inlet and said first bafiie means.

7. The combination of claim 6 wherein each of said first baffle means has a convex surface facing said inlet and a width substantially equal to the width of said tube bundles.

8. The combination of claim 7 wherein each of said second bafile means includes a first member having a convex surface facing said inlet and a plate member extending downwardly from said first member between a pair of said first bafile means.

References Cited UNITED STATES PATENTS 2,646,818 7/1953 Bimpson 134 X 2,853,279 9/1958 Switzer 165-134 3,078,919 2/1963 Brown 165l34 X FOREIGN PATENTS 469,213 12/ 1928 Germany. 853,080 10/1952 Germany.

ROBERT A. OLEARY, Primary Examiner A. W. DAVIS, Assistant Examiner U.S. Cl. X.R. 165134, 159 

